Patent GB-161088-A (GB)
Title: Locomotive stokers
IPC: F23K3/04
Filed: 1920-05-21
Abstract: 161,088. Lower, N. M. May 21, 1920. Mechanical stoking.-Fuel is transferred from the locomotive tender to the fire-box by an horizontal helical conveyer and a plurality of helical elevators discharging through apertures 55 in the furnace front, and means are provided whereby the conveyer and elevators derive intermittent motions from a common cylinder and piston 26, these motions being independently controlled. Each elevator consists of a box 17, having a fuel inlet 22, and a superimposed casing 19 (Figs. 2 and 3 showing the lower and upper portions respectively) enclosing a helical fuel conveyer 21 mounted on a hollow sleeve 23 which is loosely threaded on a shaft 24. A bar, having two tcothed racks 28, 66, is reciprocated by the piston-rod 27, and the shaft 24 is oscillated by the former rack through the medium of a pinion 29. The sleeve 23 and the shaft 24 are supported by a chambered head 33, situated above the casing 19 and containing ratchet gear, by means of retaining-rings 36, 39 respectively, the head 33 being rigidly secured to the sleeve 23 but revoluble relative to the shaft 24. Fig. 4 is a section on the line 4-4, Fig. 3, and shows a ratchet-wheel 37 which oscillates with the shaft 24 and transmits an intermittent motion to the head 33 in either direction according as pawls 41 or 42 are engaged, the pawls being arranged in pairs and. connected by springs 43 which tend to engage the pawls with the toothed ratchet-wheel 37. The opposing pawls 41, 42 are engaged or disengaged by the action of plates 44, having oblique, slots 49 engaging with pins 50 secured to the head 33, Fig. 8, the plates 44 being integral with and depending from an annular cover-plate 45 which is slidably mounted on the extension 47 of the shaft 24. A head 48 is provided to facilitate raising or lowering the cover-plate 45, which is slidably mounted on the extension 47 of the shaft 24. A head 48 is provided to facilitate raising or lowering the cover-plate 45, which movement causes a small circumferential adjustment of the plates 44 by the camming action of the pins 50 in the slots 49, and the pawls 41, 42 are consequently allowed to engage by the plates 44. In the position shown, the plate 45 is lowered and the pawls 41 are engaged, the helical conveyer 21 being intermittently revolved to elevate the fuel. When the coverplate 45 is raised both sets of pawls are disengaged, whilst a further raising engages the pawls 42, thus reversing the motion. Fig. 7 shows in section an offset inspection door 60 running longitudinally along the elevator casing 19, the door being easily removable. The lodgment of fuel in the recess effectively increases the friction of the fuel against the casing above the friction on the helix, thus avoiding the possibility of the whole mass revolving with the helix with no consequent elevation. A shield 56 and stirrers 57 are attached to the upper end of the sleeve 23 to prevent the fuel from jamming at that point. The horizontal helical conveyer is attached to the universal joint 74, Fig. 10, and derives a similar intermittent and reversible rotary motion from the rack 66 with which the pinion 30 is geared. The consequent oscillations of the ratchet-wheel 68 are communicated as an intermittent rotation to the head 69 by a system of opposed pawls as described above, the pawls being allowed to engage by the obliquely slotted plates 78. The plates 78 are integral with an annular channelled sleeve 81 slidably mounted on the: boss 70, and are operated by a forked lever 85 engaging with the channelled sleeve 81.